Are they ready?

I am now in week 10 of flowering my 100% sativas, the guideline time was 8.5 weeks. I know that the best way to see if they are ready is to look at the trichomes, i have a 30x jewelers loupe to check them but just cant decide whether or not they are cloudy as some still look clear. Is it normal for them to take this long?

thanks

sativas can take a long time for sure... pics would help